Short messaging method and system for airborne passengers

ABSTRACT

An air-to-ground telecommunications system allows callers to store messages on an aircraft data server when sufficient air-to-ground communication bandwidth is unavailable for transmitting a call. The system allows aircraft callers to leave voice, fax, e-mail or other data messages. The messages are stored on the aircraft until sufficient bandwidth becomes available for transmission to the ground. Transmitting messages requires shorter air time and more efficient bandwidth usage because messages do not require a high degree of interaction between parties. The messages can also be compressed before transmission for further efficiently using aircraft-to-ground bandwidth.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present application is related to copending application Serial Number (Attorney docket LEUCA 1-6), filed concurrently, and commonly assigned with the present invention.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to the field of telecommunications. More particularly, the present invention relates to a method and a system for communicating between parties, of which at least one party is an airborne party.

[0004] 2. Description of Related Art

[0005] Conventional communications systems allow radio-frequency (RF) communications between an airborne party, for example, on an airplane, and a ground-based party. Due to the limited radio-frequency (RF) bandwidth available for an aircraft-to-ground link, only a small number of airborne callers can use such a system at any one time. When a particular aircraft-to-ground link is filled to capacity, calls from an aircraft are placed into a queue until a channel becomes available. This is inconvenient for some callers because the purpose of the call was to convey a short message to another party and by being placed in a queue causes the call to take much longer than should be necessary. What is needed is a system that allows an airborne caller to leave a message for a ground-based caller without waiting for an aircraft-to-ground channel to become available. What is also needed is a system that compresses messages, thereby efficiently using the aircraft-to-ground bandwidth.

SUMMARY OF THE INVENTION

[0006] The present invention provides a method and a communications system that allows airborne callers to leave voice, data, or fax messages for intended recipients who are ground-based. The messages are stored on an airborne platform until sufficient bandwidth becomes available for transmission to a ground-based station. Transmitting messages requires correspondingly shorter air time and results in an efficient bandwidth usage because messages do not require a high degree of interaction between parties. The present invention further provides a system that compresses a stored message before transmission so that aircraft-to-ground bandwidth is used efficiently.

[0007] The advantages of the present invention are provided by a method and a communications system that includes a plurality of aircraft telephone units, a control unit coupled to the aircraft telephone units, a memory device that stores messages when communication bandwidth is unavailable, and a transceiver that sends and receives calls and messages to and from ground stations. An airborne party is given the option of storing a message or waiting to place the call directly when sufficient bandwidth becomes available. A stored message can be compressed before transmission and decompressed after reception, making shorter broadcast times possible. The caller is given the option of having a message sent directly to an intended recipient, or to an answering service, and a delivery receipt is transmitted to the originator of the message. Messages can be a voice message, an e-mail message, a fax message, or a data message. The message can be divided into a plurality of packets that are each transmitted separately for further improving efficient bandwidth usage.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The present invention is illustrated by way of example and not limitation in the accompanying figures in which like reference numerals indicate similar elements and in which:

[0009]FIG. 1 illustrates an aircraft short messaging system according to the present invention; and

[0010]FIG. 2 is a flow chart showing the basic steps used by the system of FIG. 1 for storing messages on an aircraft and for transmitting messages to a ground station.

DETAILED DESCRIPTION

[0011]FIG. 1 shows a schematic block diagram of an aircraft-to-ground telecommunications system that allows airborne callers to leave short messages for intended recipients who are ground-based according to the present invention. The present invention be used on airborne platforms such as airplanes, helicopters and space vehicles. Callers place and receive calls using aircraft telephone or terminal units 1. Calls can be voice, fax, e-mail or other data transmission. Outgoing calls are routed to a Cabin Telecommunications Unit (CTU) 2. CTU 2 prompts the caller in a well-known manner for obtaining call data, such as the message type, that is, whether the call is a voice call or a data call, the destination of the call and the method of payment. Once the call data has been collected and validated, CTU 2 then requests an idle air-to-ground channel from a Bearer Service System (BSS) 9. If there is sufficient air-to-ground bandwidth for the call, CTU 2 proceeds with the call.

[0012] If there is insufficient air-to-ground bandwidth for the call, CTU 2 routes the call to a voice processing circuit 3 that is part of an aircraft data server 13 for recording a short message. Voice processing circuit 3 interacts with a short message processor 4 for handling the message, such as by compressing and/or encrypting the message. Short message processor 4 prompts the caller to begin the message transfer. The message is recorded, compressed and/or encrypted and stored in a message file memory 5. Multiple messages are stored in a message data file.

[0013] Short message processor 4 receives availability status air-to-ground bandwidth via a Bearer Services System (BSS) interface (IF) circuit 8. When sufficient air-to-ground bandwidth becomes available, short message processor 4 instructs a router 6 to deliver message files stored in message files memory 5 to a ground station 11. Router 6 also performs call control functions and, if needed, multiplexing of short message file contents with data from other aircraft data server applications. Data transfer from aircraft data server 8 to the ground station 11 is accomplished via a Bearer Services System 9 and an antenna 10, employing wellknown air-to-ground communication system techniques, such as that used by AT&T's North American Terrestrial System (NATS). Ground station II forwards the short message file to a short message ground-based server 12 using well-known data communications techniques. Short message server 12 parses the received short message file into the different short messages forming the message file, decompresses and/or decrypts the respective messages and attempts to deliver each respective message to its intended destination 14. That is, voice messages are sent the destination voice terminals and data messages are sent to data terminals. Short message server 12 tracks delivery status of each respective message and provides status information to the message originator as requested by the message originator.

[0014]FIG. 2 is a flow chart showing an exemplary method for storing and transmitting message calls from an aircraft according to the present invention. At step 20, an airborne caller places a call from aircraft telephone 1. At step 21, CTU 2 determines whether bandwidth is available for transmitting the call directly. At step 22, if sufficient bandwidth is available, the call is transmitted to the ground station directly. If sufficient bandwidth is not available, at step 23 the caller is queried whether the call should be sent as a message. If the caller desires to send a message, then the caller is switched to processor 4 for recording and storing a short message at step 24. When processor 4 determines that bandwidth is available, the stored message is transmitted to a ground station at step 25. Upon receipt at the ground station, the message is decompressed at step 26. At step 27, the message is sent to the dialed number, which may be the intended recipient or an answering service. At step 28, a delivery receipt is sent to the originator of the message.

[0015] If the caller opted not to store a message at step 23, then the caller can wait in a queue at step 29 until sufficient bandwidth becomes available for placing the call directly to the dialed number at step 30. 

What is claimed is:
 1. A method for transmitting a call, the method comprising the steps of: receiving a call at a controller from a local terminal, the call being directed to a remote terminal; determining whether sufficient communication bandwidth is available for transmitting the call to the remote terminal; storing a message in a memory device when sufficient communication bandwidth is not available for transmitting the call; transmitting the message to the remote terminal when sufficient bandwidth becomes available for transmitting the message.
 2. The method of claim 1, wherein the controller, the local terminal and the memory device are on an airborne platform.
 3. The method of claim 2, wherein the step of determining whether sufficient communication bandwidth is available includes the step of providing an option to an originator of the call of recording the message before transmission.
 4. The method of claim 2, further comprising the step of receiving a delivery receipt at the local terminal when the message is delivered to the remote terminal.
 5. The method of claim 2, further comprising the step of compressing the recorded message before the step of transmitting the message to the remote terminal.
 6. The method of claim 2, further comprising the steps of: dividing the message into a plurality of packets; and transmitting each packet separately.
 7. The method of claim 2, wherein the message is one of a voice message, a data message, a fax message and an e-mail message.
 8. The method of claim 7, wherein the message is delivered to one of an intended recipient of the message and an answering service.
 9. A communications system, comprising: a plurality of local terminal units; a transmitter transmitting calls to a remote terminal; control unit coupled to the local terminal units, the control unit receiving a call from one of the plurality of local terminal units and determining whether communication bandwidth is available for transmitting the call from the transmitter; and a memory device, coupled to the control unit, storing a message when transmitter communication bandwidth is unavailable.
 10. The system of claim 9, wherein the local terminal units and the memory device are on an aircraft.
 11. The system of claim 10, wherein the processor provides an option for an originator of the call for storing a message before transmission.
 12. The system of claim 10, wherein the local terminal unit receives a delivery receipt when the message is received by the remote terminal.
 13. The system of claim 10, wherein the processor compresses the message before transmitting to the remote terminal.
 14. The system of claim 10, wherein the processor divides the message into a plurality of packets that are each transmitted by the transmitter separately.
 15. The system of claim 10, wherein the stored message is one of a voice message, a data message, a fax message and an e-mail message.
 16. The system of claim 15, wherein the transmitter transmits the message to one of an intended recipient and an answering service.
 17. A communication method, comprising: receiving a call request; selecting a call service bandwidth; determining an initial available bandwidth; and transmitting the call if the initial available bandwidth is greater than or equal to the call service bandwidth.
 18. The method of claim 17, further comprising routing the call request to a call processor configured to store the requested if the available bandwidth is less than the call service bandwidth.
 19. The method of claim 17, wherein the call request is a request for transmission of a voice call.
 20. The method of claim 17, wherein the call request is a request for transmission of a fax.
 21. The method of claim 17, wherein the call request is a request for transmission of an email.
 22. The method of claim 17, further comprising storing the call if the available bandwidth is less than the call service bandwidth.
 23. The method of claim 22, further determining a subsequent available bandwidth, and transmitting the stored call if the subsequent available bandwidth is greater than or equal to the call service bandwidth.
 24. The method of claim 22, further comprising periodically determining a subsequent available bandwidth until the subsequent available bandwidth is greater than or equal to the call service bandwidth and the stored call is transmitted.
 25. The method of claim 22, wherein the stored call is combined with at least one other stored call in a message file; and further comprising determing a subsequent available bandwidth and transmitting the message file if the subsequent available bandwidth is greater than the call service bandwidth.
 26. A call processor, comprising: a bandwidth determination unit configured to determine an available communication bandwidth; and a call transmitter configured to transmit a call if the available bandwidth is greater than a bandwidth associated with the call.
 27. The call processor of claim 26, further comprising a memory configured to store the call.
 28. The call processor of claim 27, wherein the memory is configured to store and combine a plurality of calls and the call transmitter is configured to transmit the plurality of calls if the available bandwidth is greater than a bandwidth associated with the plurality of stored calls.
 29. A communication method, comprising: requesting a call bandwidth associated with a call request; determining an available bandwidth of an available communication channel; and delivering a call to the available communication channel if the call bandwidth is less than or equal to the available bandwidth.
 30. The communication method of claim 29, further comprising queuing until the available bandwidth is greater than or equal to the call bandwidth.
 31. The communication method of claim 29, further comprising storing the call until the available bandwidth is greater than or equal to the call bandwidth.
 32. A message processor, comprising: an input configured to receive a bandwidth associated with a call and a bandwidth of an available communication channel; and an output configured to authorize transmission of the call if the bandwidth of the available communication channel is greater than the call bandwidth.
 33. A communication system, comprising: a plurality of local communication units; a control unit configured to receive calls from originators at one or more of the plurality of local communication units and to establish a call bandwidth; a control unit configured to determine an available bandwidth of an idle communication channel; and a transmitter configured to transmit the received calls if the available bandwidth is greater than or equal to the call bandwidth.
 34. A telecommunications unit, comprising: a call input configured to receive a call from a call originator; a call prompter configured to request call data from the call originator; a channel requester configured to request an idle communication channel; an input configured to receive an indication of an available bandwidth of the idle communication channel; and a call transmission output configured to direct completion of the call if the indicated available bandwidth is greater than or equal to a bandwidth associated with the call received from the call originator.
 35. The telecommunications unit of claim 34, further comprising a memory configured to store the call from the call originator.
 36. The telecommunications unit of claim 35, wherein the call transmission output is configured to transmit the stored call if the indicated available bandwidth is greater than or equal to a bandwidth associated with the call received from the call originator. 